Thanks for your posting. TestRail doesn’t have a built-in requirement management module, because we found that most teams prefer to manage their requirements/user stories/feature requests within their issue tracker such as JIRA, wiki software or dedicated requirement management tools. That said, you can link test cases to externally stored requirements via TestRail’s References field. You can learn more about the References field on our website here:
TestRail also comes with various reports for requirements and other metrics. For example, you can generate traceability and coverage reports for requirements or defects from the Reports tab. The most popular tool for managing requirements or user stories together with TestRail would be JIRA and we have a very advanced JIRA integration:
I hope this helps!